JP4297750B2 - Power steering device - Google Patents

Description

  The present invention relates to a power steering device provided in an industrial vehicle such as a forklift or a wheel loader.

Conventionally, as this type of power steering apparatus, a configuration in which a steering shaft is interposed between a handle and a pressure oil supply device is provided (see, for example, Patent Document 1).
Specifically, the handle side is configured to be tiltable back and forth with respect to the main body side so that it can be adjusted according to the body shape of the driver, etc., and the pressure oil feeder is positioned at a fixed position on the main body side. It is fixed to. For this purpose, the steering shaft is composed of a shaft to which the steering wheel is connected and a universal joint or intermediate shaft that interlocks and connects the shaft and the pressure oil supply device. Is absorbed.
Japanese Patent Laid-Open No. 8-156683 (page 2-4, FIG. 3-4)

However, according to the above-described conventional configuration, a universal joint, an intermediate shaft, and the like are required, so that the entire power steering apparatus has a complicated structure and high cost.
SUMMARY OF THE INVENTION An object of the present invention is to provide a power steering device that can omit a universal joint, an intermediate shaft, and the like.

In order to achieve the above-mentioned object, a power steering device according to claim 1 of the present invention uses a rotary type switching valve, and rotates the rotor by an amount corresponding to the rotation angle of the spool of the switching valve. When the pressure oil supplied from the hydraulic pump that has been pushed off is sent to the steering cylinder that is connected to the downstream side of the switching valve and switches the turning angle of the wheel, the hydraulic pump stops and no pressure oil is supplied. A pressure oil feeder is configured to operate as a hand pump that feeds oil to the steering cylinder, and a shaft having a handle connected to the upper part is inserted into the column and rotatably supported on the column side. the member attached to the provided, the mounting member is Rutotomoni is formed in a state having a horizontal plate portion and a pair of vertical plate portions, both vertical plate portion its Together swingably connected, connecting the pressure oil supply to the transverse plate portion of the mounting member to the pair of support members from the main body side via the quadrature-shaped tilt fulcrum Re to the shaft axis respectively, this A lower portion of the shaft is interlocked to a spool of a pressure oil feeder, and one support member of the pair of left and right support members protrudes upward, and an upper end portion of the one support member and an intermediate portion of the column A tilt handle fixing means is provided between them.

Therefore, according to the first aspect of the present invention, the column can be fixed to one of the support members by loosening the tilt handle fixing means. In this state, when a pushing / pulling force is applied to the handle, the pushing / pulling force can be transmitted to the mounting member via the shaft or the column, so that the mounting member is rotated around the tilt fulcrum with respect to both support members . Can move. At this time, the pressure oil feeder connected to the mounting member also rotates around the tilt fulcrum, and the interlocking connection between the shaft and the spool is maintained, and thus the interlocking by only one shaft is performed. Although it is configured, tilting (tilting) forward and backward of the power steering device with respect to the main body side can be performed smoothly.

Thereafter, the column can be fixed to one of the support members by fixing the tilt handle fixing means , whereby the handle can be adjusted according to the body shape of the driver. And normal operation can be performed by rotating the handle in the forward and reverse directions. At this time, the rotation of the handle can be transmitted to the spool of the pressure oil supply device through only one shaft. The oil supply unit can be operated to supply and discharge pressure oil.

The power steering apparatus according to claim 2 of the present invention, in the configuration of claim 1, wherein the above, the mounting member is bent formed into a U-shape in a state having a horizontal plate portion and a pair of vertical plate portions to have a call in which was characterized by.

  Therefore, according to the second aspect of the present invention, the structure in which the pressure oil feeder is located near the tilt fulcrum can be realized with a simple structure.

According to the first aspect of the present invention, the column is fixed to one of the supporting members by loosening the tilt handle fixing means, and the pushing / pulling force is applied to the handle in this state. Can be transmitted to the mounting member via the shaft or column, so that the mounting member can be rotated around the tilt fulcrum with respect to both support members . At this time, the pressure oil feeder connected to the mounting member also rotates around the tilt fulcrum, so that the interlocking connection between the shaft and the spool can be maintained, and thus the interlocking configuration is based on only one shaft. However, tilting (tilting) forward and backward of the power steering apparatus with respect to the main body side can be performed smoothly.

Thereafter, the column can be fixed to one of the support members by fixing the tilt handle fixing means , whereby the handle can be adjusted according to the body shape of the driver. And normal operation can be performed by rotating the handle in the forward and reverse directions. At that time, the rotation of the handle can be transmitted to the spool of the pressure oil supply device through only one shaft, thereby Pressure oil can be supplied and discharged by operating the feeder.

  As a result, a low-cost power steering device can be provided as a whole without the universal joint and intermediate shaft. Moreover, the pressure oil feeder can be located near the tilt fulcrum, and the operating range (swing range) of the pressure oil feeder during tilting can be reduced, thereby ensuring sufficient clearance for the foot brake part of the driver's seat. The tilt of the handle can be greatly adjusted by setting the tilt fulcrum to a position close to the handle.

  According to the second aspect of the present invention, the structure in which the pressure oil feeder is located near the tilt fulcrum can be easily realized with a simple structure.

Although the universal joint and intermediate shaft are omitted, the power steering device can be tilted smoothly before and after the power steering device.
[Embodiment]
Embodiments of the present invention will be described below with reference to the drawings.

  First, in FIG. 7 and FIG. 8, the configuration and operation of the pressure oil supplier 11 will be described. That is, in a state where the handle (details will be described later) 5 is set to the straight traveling position, the spool 13 of the switching valve portion 12 in the pressure oil supplier 11 is in the C position, and the pressure oil is not supplied to the steering cylinders 14 and 15. .

  Then, when the handle 5 is rotated counterclockwise from the straight traveling position, the spool 13 is switched from the C → L position, and the pressure oil from the hydraulic pump 16 flows into the pressure oil feeder 11 through the steering priority flow rate adjusting valve 17. Further, the pressure oil flows through the metering portion 18 and the spool 13 into the tail side of the first steering cylinder 14 and the rod side of the second steering cylinder 15. At the same time, the pressure oil on the rod side of the first steering cylinder 14 and the tail side of the second steering cylinder 15 flows into the recovery tank 19 through the spool 13. When a predetermined amount of pressure oil is supplied to both the steering cylinders 14 and 15 and the wheels are switched by a predetermined angle, the spool 13 is switched to the L → C position, and the supply of pressure oil to both the steering cylinders 14 and 15 is performed. Stopped.

  Further, when the handle 5 is rotated clockwise, the spool 13 is switched from the C → R position, and the pressure oil flows into the tail side of the second steering cylinder 15 and the rod side of the first steering cylinder 14, The pressure oil on the rod side of the second steering cylinder 15 and the tail side of the first steering cylinder 14 is collected in the collection tank 19.

  Further, the operation of the pressure oil supplier 11 will be described. When the handle 5 is rotated counterclockwise, the spool 13 rotates via a shaft (details will be described later) 31. It is displaced to. As a result, the oil passage is opened, and the pressure oil (dotted arrow A) flowing in from the P port 22 passes through the oil hole of the switched sleeve 21, the oil groove of the spool 13, and the oil hole of the sleeve 21. The rotor 24 is rotated from the oil passage to the metering unit 18.

  The pressure oil discharged by the rotation of the rotor 24 (the one-dot chain line arrow B) is sent to the switching valve section 12, and from the L port 25 through the sleeve 21 and the spool 13, the tail side of the first steering cylinder 14 and the second side It flows into the rod side of the steering cylinder 15. At the same time, the pressure oil (the two-dot chain arrow C) on the rod side of the first steering cylinder 14 and the tail side of the second steering cylinder 15 is discharged and returned to the R port 26, via the sleeve 21 and the spool 13. Outflow from T port 27.

  Here, when the rotor 24 rotates as described above, both the drive shaft 28 and the sleeve 21 rotate. That is, when the spool 13 is rotated by turning the handle 5, the sleeve 21 is rotated by the same amount following the spool 13 to eliminate the displacement of the spool 13, and the oil passage of the switching valve portion 12 is fully closed. As a result, the rotor 24 rotates by an amount corresponding to the rotation angle of the handle 5, and the pressure oil pushed away by the rotor 24 is sent to both the steering cylinders 14 and 15.

  Further, when the handle 5 is rotated clockwise, the rotor 24 rotates in the reverse direction, and the suction and discharge of the rotor 24 are reversed. As a result, the pressure oil flows from the R port 26 to both the steering cylinders 14 and 15, and the pressure oil discharged from both the steering cylinders 14 and 15 returns to the L port 25.

  Further, when the hydraulic pump 16 stops due to the engine stop of the vehicle or the like and the pressure oil is no longer supplied, the pressure oil supplier 11 becomes an emergency manual steering device. That is, when the spool 13 is rotated by a predetermined angle, it collides with the cross pin 29, the cross pin 29 rotates the rotor 24 via the drive shaft 28, and the metering portion 18 operates as a hand pump that sends oil to both the steering cylinders 14 and 15. .

  According to the above 12, 13, 18, 21 to 29, etc., a rotary type switching valve is used, the rotor 24 is rotated by the rotation angle of the spool 13 of this switching valve, and the hydraulic pressure displaced by the rotor 24 is removed. The pressure oil supplied from the pump 16 is sent to the steering cylinders 14 and 15 that are connected to the downstream side of the switching valve and switch the turning angle of a wheel (not shown), and the hydraulic pump 16 stops and the pressure oil is stopped. When oil is not supplied, an example of the pressure oil supplier 11 configured to operate as a hand pump that sends oil to the steering cylinders 14 and 15 is configured.

Next, details of the power steering apparatus 10 including the pressure oil supplier 11 having the above-described configuration will be described with reference to FIGS.
The shaft 31 is in the form of a single rod, and the handle 5 is connected to the upper portion thereof, and the lower portion thereof is interlocked and connected to the spool 13 of the pressure oil supply device 11. That is, the central boss portion 6 of the handle 5 is fitted on the upper portion of the shaft 31, and the nut body 32 is screwed to the screw portion 31 a formed on the upper portion of the shaft 31. Are concatenated. The handle 5 is provided with a knob 7 for facilitating the rotation operation.

  The shaft 31 is inserted into a cylindrical column 33 and is rotatably supported by the column 33. That is, the upper cylindrical body 34 is fixed to the upper end of the column 33, and the upper portion of the shaft 31 is rotatably supported by the bearing 35 fitted in the upper cylindrical body 34. At that time, the bearing 35 is positioned on the upper cylindrical body 34 side by the snap ring 36.

  An attachment member 37 is provided at the lower portion of the column 33, and the attachment member 37 is swingably connected to the front cover (an example of the main body side) 1 via a tilt fulcrum 43 orthogonal to the shaft axis 31A. ing. That is, a lower cylindrical body 38 is fixed to the lower end of the column 33, and an attachment member 37 is externally fixed to the lower cylindrical body 38. Here, the attachment member 37 is bent and formed in a U-shape with a horizontal plate portion 37a and a pair of left and right vertical plate portions 37b, and the column member 33 is formed through a through hole 37c formed in the central portion of the horizontal plate portion 37a. It is fixed by welding or the like with the lower end fitted.

  A pair of left and right screw holes 37d are formed in the pair of vertical plate portions 37b, and a pair of left and right support members 2A and 2B from the front cover 1 side are rotatably supported via bushes 39. The bolt bodies 40 are respectively screwed into the screw holes 37d, so that both the vertical plate portions 37b are swingably connected to the front cover 1 side via a tilt fulcrum 43 formed of a rotation axis by the bolt body 40. Has been.

  The pressure oil supplier 11 is connected to the horizontal plate portion 37 a of the mounting member 37, and the lower portion of the shaft 31 is interlocked to the spool 13 of the pressure oil supplier 11. That is, the housing 23 of the pressure oil feeder 11 is applied to the horizontal plate portion 37a from below, and a plurality of bolt bodies 41 passed through the horizontal plate portion 37a from above are screwed to the housing 23 side. Thus, the pressure oil supplier 11 is connected to the lower surface of the horizontal plate portion 37a. At that time, the spline shaft portion 31 b formed at the lower portion of the shaft 31 is inserted into the spline hole portion 13 a formed at the upper portion of the spool 13, whereby the lower portion of the shaft 31 is interlocked and connected to the spool 13.

  A tilt handle fixing means 45 is provided between the intermediate portion of the column 33 and the front cover 1 side. That is, a connecting member 46 is attached to the outer surface side of the intermediate portion of the column 33 by welding or the like, and a screw hole 47 in the left-right direction is formed in the connecting member 46. One support member 2B protrudes upward, and its upper end is brought into contact with the connecting member 46 from the outside. Further, an arc-shaped elongated hole 3 centered on the tilt fulcrum 43 is formed at the upper end portion of the support member 2B. The bolt-shaped lock body 48 has a threaded portion 48 a passed through the elongated hole 3 from the outside and is screwed into the threaded hole 47. The lock body 48 is provided with an operation lever 49 for rotation. An example of the tilt handle fixing means 45 is constituted by the above 3, 46 to 49 and the like.

  An upper bracket 51 is connected to the column 33 at its upper end, an intermediate bracket 53 is connected to an intermediate portion near the connecting member 46, and a lower bracket 54 is connected to the lower portion of the intermediate bracket 53 by welding or the like. . The upper bracket 51 is used for mounting the combination device 55, the intermediate bracket 53 is used for mounting the meter panel 56, and the lower bracket 54 is used for mounting the cover body 57.

The operation in the above embodiment will be described below.
For example, in the state of the solid lines in FIGS. 1 and 6, the driver rotates the lock body 48 via the operation lever 49 and loosens the screw portion 48a to the screw hole 47, thereby connecting the support member 2B to the connecting member. The pressure bonding (fixation) of 46 can be released. When a pushing force is applied to the handle 5 in this state, the pushing force is transmitted to the mounting member 37 via the shaft 31, the bearing 35, the upper cylindrical body 34, the column 33, and the lower cylindrical body 38. 2 and 6, the attachment member 37 is rotated around the tilt fulcrum 43 with respect to the support members 2A and 2B.

  At this time, the pressure oil supplier 11 connected to the attachment member 37 also rotates around the tilt fulcrum 43, and the interlocking connection between the shaft 31 and the spool 13 is maintained. In this way, the power steering device 10 can be tilted forward with respect to the front cover (main body side) 1 smoothly at a desired angle θ. Thereafter, the lock member 48 is rotated reversely to the above through the operation lever 49, and the screw portion 48a is screwed into the screw hole 47, whereby the connecting member 46 can be pressure-bonded (fixed) to the support member 2B. . Thus, the handle 5 can be adjusted according to the body shape of the driver.

  In addition, by applying a pulling force to the handle 5 in a state where the crimping (fixing) of the connecting member 46 to the support member 2B is released, the power steering device 10 for the front cover (main body side) 1 contrary to the above. The tilt (tilt) to the rear of the can be performed smoothly.

  Note that tilting forward and backward of the power steering device 10 is regulated by the allowable movement range of the lock body 48 in the long hole 3. Further, the tilting forward and backward is performed with the cover body 57 being integrated.

  The normal operation can be performed by rotating the handle 5 in the forward and reverse directions. At this time, the rotation of the handle 5 can be transmitted to the spool 13 of the pressure oil feeder 11 through only one shaft 31. . Furthermore, the rotation of the handle 5 can be carried out smoothly without being adversely affected by the steering force due to misalignment or the like by the support by the bearing 35 provided at the upper part of the column 33, and the bearing 35 is formed in a higher cylindrical shape by the snap ring 36. By positioning on the body 34 side, the rotation support mechanism of the handle 5 can be provided with a simple structure and at a low cost.

In the above-described embodiment, the attachment member 37 is bent and formed in a U shape in a state having the horizontal plate portion 37a and the pair of vertical plate portions 37b. configuration the vertical plate portion are integrated by welding, or may etc. configuration that is formed into an inverted U-shape.

FIG. 3 is a left side view with a part cut away at an intermediate position of the power steering device according to the embodiment of the present invention. It is a partially cutaway left side view at the forward push adjustment position in the power steering device. It is a partially cutaway front view of the power steering apparatus. FIG. 4 is a partially cutaway front view of a tilt handle fixing means portion in the power steering device. It is a partially cutaway front view in the shaft part of the same power steering device. It is a partially cutaway left side view of the main part at an intermediate position of the power steering device. It is a longitudinal cross-sectional view of the pressure oil supply part of the power steering device. FIG. 3 is a hydraulic circuit diagram of the power steering device.

Explanation of symbols

1 Front cover (on the main unit)
2A Support member 2B Support member 3 Long hole 5 Handle 6 Central boss part 10 Power steering device 11 Pressure oil supply device 12 Switching valve part 13 Spool 13a Spline hole part 14 Steering cylinder 15 Steering cylinder 16 Hydraulic pump 18 Metering part 23 Housing 24 Rotor 28 Drive shaft 31 Shaft 31b Spline shaft portion 31A Shaft axis 33 Column 34 Upper cylindrical body 35 Bearing 36 Snap ring 37 Mounting member 37a Horizontal plate portion 37b Vertical plate portion 38 Lower cylindrical body 40 Bolt body 41 Bolt body 43 Tilt Support point 45 Tilt handle fixing means 46 Connecting member 48 Lock body 49 Operation lever

Claims (2)

Using a rotary switching valve, the rotor is rotated by the rotation angle of the spool of this switching valve, and the pressure oil supplied from the hydraulic pump displaced by this rotor is connected to the downstream side of the switching valve. The pressure oil feeder is configured to operate as a hand pump that sends oil to the steering cylinder when the hydraulic pump stops and pressure oil is no longer supplied. The shaft with the handle connected to the upper part is inserted into the column and is supported rotatably on the column side, and an attachment member is provided at the lower part of the column . The attachment member has a horizontal plate part and a pair of vertical plate parts. It is formed in a state having Rutotomoni, right and left pair of support members from the main body side via the quadrature-shaped tilt fulcrum both vertical plate portion to the shaft axis respectively Swingably connected, the with coupling the pressure oil supply to the transverse plate portion of the mounting member, the lower spool of the shaft of the pressure oil supply interlock connected, out of the pair of right and left support members One of the support members protrudes upward, and a tilt handle fixing means is provided between the upper end portion of the one support member and an intermediate portion of the column. Mounting member, the power steering apparatus according to claim 1, wherein in a state having a horizontal plate portion and a pair of vertical plate portions, characterized that you are bent formed into a U-shape.

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